Field of the Invention
The present invention relates to a method for producing a fiber having a pattern on a surface thereof, and a fiber produced by the method.
Related Art
Studies on providing of concaves and convexes on the surface of a fiber have hitherto been made for attaining various purposes such as an improvement in touch feeling and texture. For example, Patent Document 1 proposes a method for producing a composite fiber having concaves and convexes on a surface thereof, the method comprises subjecting a polyester composition containing 20 to 50% by mass of a poly(meth)acrylate resin and a polyester free from a poly(meth)acrylate resin to composite spinning, taking off an unstretched yarn at a speed of not more than 3500 m/min; followed by stretching the unstretched yarn at a stretching temperature of 55 to 95° C. by a factor of 0.62 to 0.91 of the maximum stretch ratio.
On the other hand, extrafine fibers such as nanofibers having a thickness on a nanometer order have drawn attention, for example, from the viewpoints of a high level of absorptivity by virtue of a larger surface area, a reduction in pressure loss by virtue of the occurrence of a slip stream in filter applications, excellent optical properties that can easily provide highly transparent fabrics, and excellent electric characteristics, kinetic properties, and thermal properties derived from a supermolecule alignment effect.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2001-164428